Electric plug



E. CARDONE ELECTRIC PLUG Aug. 17, 1954 Filed July 6, 1951 INVENTOR.'UGE/V' C4EOGN Patented Aug. 17, 1954 ELECTRIC PLUG Eugene Cardone,Jamaica, N. Y.

Application July 6, 1951,

Serial No. 235,401

8 Claims. (Cl. 200-115.5)

This invention relates to an electric plug and more particularly to anelectric plug containing a removable and replaceable safety fuse prongtherein.

In most homes where electricity is used it will be noted that there isprovided a fuse box at the electrical power line entering the house orbuilding concerned. Such homes are also prcvided with a number ofelectric outlets at the base or floor boards in the various rooms inaddition to the electrical outlets for ceiling lighting and otherfixtures. In many instances and particularly where there cult of thepower when the whole line with all lighting units and sockets controlledby such fuse is out and a search would have to be made throughout thehouse or building to determine where the blow-out occurred. The user ofthe electricity then would have to go the fuse box and replace the blownfuse with a good one, the fuse boxes being usually located in the cellarof the house or building thereby necessitating xtra walking andinconvenience to the person changing the fuse.

With the above noted and other disadvantages in view, it is an object ofmy invention to provide an electrical plug containing one or morereadily removable fuse containing prongs which may be readily insertedinto the wall sockets of an electrical line or into electricalreceptacle outlets.

Another object of my invention is to provide an electrical plug with oneor more easily replaceable fuse terminals to facilitate the location andelimination of short circuits in electrical circuits.

Another object of my invention is to provide an easily constructedelectricity conducting wall in which one of the prongs thereofconstitutes a fuse integral therewith and which can be easily removedand replaced if the fuse in such prong is blown out.

Still another object of my invention is to provide a plug for use inelectric sockets or electrical receptacle outlets now in general use,said plug including tensioned holding means and a removable terminalprong therein having an insulated fusible material forming an integralpart of the prong. I

Other objects and features of this invention will become apparent fromthe following description taken in conjunction with the accompanyingdrawings, in which:

Fig. 1 is a sectional vertical view of a preferred embodiment of myinvention taken on line II of Fig. 2;

Fig. 2 is a bottom ment;

Fig. 3 is a fragmental side view of a prong and fuse integral therewithin the embodiment shown in Fig. 1;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a perspective view of a spring holding member or housing forone of the terminals forming part of the embodiment shown in Fig. l;and,

Fig. 6 is a sectional view taken on line 6-5 of Fig. 5.

Referring now more particularly to the drawings in which similarreference numerals refer to like parts throughout, I provide a plug l [Iwith a body l0 made of any suitable material hav ing a high electricalinsulation quality, such as hard rubber, Bakelite and the like. Saidplug Ill is provided with a central longitudinal opening I I throughwhich extends an insulated sheath containing wire conductors I2 and I3diverging from said central opening into a well I4 in the plug body It.Said well I4, as will be noted from the drawing, is a depression orrecess set in from the base or socket contacting portion I5. Said wellhas disposed at one side of its longitudinal axis a right angledterminal member or prong I6 extending upwardly from the bottom I!thereof being held in relatively fixed position to said bottom I7 bymeans of one or more pins I8. Said terminal I6 has a shorter arm I9fixed to the bottom I? of well I4 by pins I8 and is provided with athreaded opening I9 therethrough for accommodating a screw member 20 forholding conductor I2 against said short arm I9 plan view of my embodi-To the other side of opening II of said plug and diametrically oppositethe area of arm I9 there is a deep vertical recess 2I for accommodatinga spring housing or detent member 22. It will be noted that said housing22 has a laterally extending arm 23 which rests on the bottom I! of wellI4. Said arm 23 is held in position in said recess and bottom of well I4by means of pin 24 extending through opening 24 into said bottom I7.Said housing as shown more clearly in Figs. 1 and 5 also has an upwardlyextending relatively stiff section 25 integral with arm 23, a bent flatbottom section 26 and an upwardly extending curved yieldable springsection 21. Said spring section 21 is provided with a pair of inwardlybent opposed guide tabs 28 which are perpendicular to the plane of thespring, while the upper part of the spring section is curved inwardlyand then outwardly forming the tongue or upper free end 29. Upwardsection 25 is provided with a semi-circular hole 38 as shown in Fig. 6.

It will be noted that spring housing or detent 22 forms a housing for aremovable terminal or prong 3i whose upper part is substantially of thesame construction as prong it but whose lower part is provided with afuse strip 32 for accommodating any type of amperage. Said strip 32 isconnected to the metallic terminal iii in any suitable manner such as bysoldering or cementing and is an integral part therewith. The lowerportion of said fuse strip 32 forms part of and extends into and isconnected with a metal base or cup 33 having one or more peripherallyextending tongues or projections 3t. Said fuse strip is covered orcoated with a transparent insulator 35 made of non-conducting plastic,glass or other suitable material. It will be noted that this insulatorextends upwardly from the bottom of metal cup 33 to the prong 3i therebycompletely encasing the strip 32. Further, the said cup 33 is inelectrical contact with the fuse strip and the detent 22, as shown.

Said prong M with its appurtenent parts can be readily inserted into ormoved from the spring housing Upon insertion of the prong 3i with itsfuse unit into the housing 22, the lower portion of said prong slidesinto the spring housing so that its sides are in contact with theupwardly extending section 25 and tongue 29. The latter because of itstension presses the prong against section 25 and as said prong isfurther pushed into the housing one of the projections 3:2, 1. e., theone abutting section 25 will be caught by the opening 30 in section 25thereby rigidly retaining the terminal in position in the spring housingin said plug is.

If upon use of the plug herein described the fuse strip is blown and itis desired to replace the prong 3!, it is pressed laterally against thecurved free end 29 thereby permitting the projection 3a to slide fromopening at whereupon the prong 3i is withdrawn.

It will be noted as shown in Fig. i that the bottom ii of well i l issomewhat lower at the recess area 2! than the bottom where the arm in ofprong i6 is set. This is done to prevent wire conductor l3 when held inposition against arm 23 by means of screw 36 in threaded opening 3'5from interfering with the removal or insertion of prong 3!. It will alsobe noted that fixed prong member is may be replaced by a removable prongwith built-in integral fuse exactly the same as prong 3i with itsarrangement of parts to allow easy removal and insertion of saidprong-fuse combination 3!. Said plug would then be equipped with tworemovable prong-fuse combinations 3 I.

From the foregoing description taken in conjunction with theaccompanying drawings, it will be noted that by my invention I provide asafe and economic plug in which one or more of the prongs or terminalsacts as a fuse thereby reducing the amount of inconvenience in replacingor locating blown fuses. Also, the whole line in the circuit is notblown, and it will be further noted that the short will be in the lineleading to a particular fixture or appliance. A plug made according tomy invention has one Or more fuse prongs which are as rigid as theconventional type of plug. Because of the interlocking feature providedin the plug there is little or no likelihood of the prongs becomingloose or of being easily removed from the plug itself. Such type of plugalso has a well in which the floor thereof is set at different levels soas to prevent wire conduits extending into the plug from interferingwith the removability or insertion of the replaceable fuse prong memberor terminal. Such plug, according to my invention, is safe to use andthe fuse containing prong removed and replaced with ease andconvenience.

While a preferred embodiment of my invention has been shown anddescribed it is to be understood that various modifications as to form,arrangement of parts and use of materials may be made without departmentfrom the spirit and scope of the invention as claimed.

I claim:

1. In an electric plug for use in combination '7 with electricalreceptacle outlets now in general use, having a base insulated memberfor holding a pair of wire conductors from a source of electricity, saidplug having a recess therein, the improvement comprising anelectroconductive fixed terminal member in said recess in connectionwith one of the conductors and extending outwardly of the base member,said recess having a bore extending deeper into the than the recessitself, an electroconductive tensicned housing member set in said bore,said member being in connection with the other wire conductor, andremovable electroconductive terminal member fixed in said housing memberfor completing the electric circuit when set in a socket and the like,said removable terminal member having an upper metallic part and a lowerpart provided with a fuse strip and a metal base making electricalcontact with the housing, and a transparent insulator of non-conductingmaterial housing said fuse strip, said insulator extending upwardly ofthe metal base and beyond the housing member.

2. In an electric plug for use in combination with a conventionalelectrical receptacle having a base member having a central openingtherein for electrical wiring, a well set inwardly of one end of saidbase member forming a recess for accommodating the terminals of saidwiring, the improvement comprising a pair of terminal prong members eachin connection with said wiring, one of said prong members being setpermanently in the well, and the other is provided with a fusible metalstrip integral therewith, and coated with insulated material and aspring housing set inwardly of the recess for removably retaining thelast named prong member, said housing having an extension fixed to thewell, and a portion adapted to hold the last named pronged member inrelatively fixed position therein.

3. In an electric plug for use in combination with conventionalelectrical receptacle outlets having a base member having an openingextending therethrough for electrical wiring, a well set inwardly of theend of said base member facing the outlet, said flooring being adaptedfor accommodating the terminals of said wiring, the improvementcomprising a pair of terminal prong members in connection with saidwiring, one of said prong members being fixed in said well and connectedwith one of the wiring, the other of said prong members being removableand having a fusible strip integral therewith and covered withtransparent insulated material, and a spring tensioned housing inelectrical contact with the strip and set in the base member inconnection with the other of said wiring and adapted to accommodate andlock said last named prong member said housing forming electricalcontact with the bottom of the removable prong member thereby completingthe electrical circuit from one prong member to the other when the plugis connected with a source of electricity.

4. A plug according to claim 3, in which the housing has a flat wall andan opposed inwardly curved spring wall, and notched retaining means inthe flat wall for fixedly engaging the removable prong member.

5. A plug according to claim 3, in which the bottom of the well aroundthe removable prong is slightly elevated relative to the flooring aroundthe fixed prong to permit easy removal of the prong member withoutinterference from the terminal of the wiring leading to said last namedprong member.

6. In an electric plug for a conventional socket having a base ofinsulating material havin an opening extending therethrough foraccommodating electrical wiring, said base having a well of differentlevels set inwardly of one end of said base member for accommodating theterminals of said wiring, the improvement comprising a pair of bindingposts, a pair of terminal prongs in electrical connection with saidwiring, and connectible with the posts, one of said prongs beingremovable and having a fusible strip integral therewith and coated withinsulated material, the level of the well around the former prong beinglower than the level around the removable prong,

prong, and interengaging electrical contacting means on said last prongand the housing for keeping the prong in fixed position in the base andcomplete the electric circuit when in connection with a source ofelectricity.

7. In a removable plug, a removable prong acting as a fuse, comprisingan electric conducting exposed member, a fusible alloy strip conwardlyof the holder for enclosing the strip and part of the member to preventshorting in the plug, said alloy strip being in electrical connectionwith the holder housing.

8. In an electrical plug for use in the conventional type of electricalreceptacle outlets having a non-conducting base member having a recessedwell facing the outlet when connected therewith and an opening for thepassage of wiring therethrough to the recessed well, a pair of bindingposts in said well for electrical connection with the wiring, theimprovement comprising a terminal prong member in connection with one ofposts, a spring locking housing set in the base in electrical connectionwith the other post, and another terminal having a fuse integraltherewith set in the spring locking housing, said fuse being insulatedwhereby the bottom of the terminal forms electrical contact with thehousing, said last terminal having interlocking means for said housingand being integrally replaceable and removable from the housing.

References Cited in the file of this patent UNITED STATES PATENTS

